In blood tests or exhaled breath condensation tests, it is important to authenticate the test because it is possible that someone other than the intended subject is actually tested, either inadvertently or deliberately. Here the term “intended subject” refers to a person that is scheduled/required to be tested in a specific blood-testing session by a testing professional, agency or entity. In some cases, for example, an imposter can replace the intended subject and provide a blood sample of his/her own; in some other circumstance, especially in remote blood testing, the intended subject can provide a blood sample not from himself/herself, but from someone else. Therefore, at least two problems arise: (1) authenticating that the subject being tested is actually the intended subject; and (2) authenticating that the sample being collected is actually a sample from the subject being tested, not from someone else. The present invention provides solutions to these problems.